Such applicators are intended for single handed operation by an operating surgeon. Examples of such applicators are described in international patent application publication numbers WO 2005/039422 and WO-A-01/12079.
Such clips may be used for sterilisation or other medical, orthopaedic or surgical purposes. An example is the “Filshie” clip which is disclosed in GB patent number 2177748.
Certain known applicators for such clips, as disclosed for example in WO 2005/039422, use a pushrod and associated linkage mechanism to cause rotation of an articulated jaw to produce compression forces on a clip and to thereby compress the clip causing it to close, preferably with a latching action. The compression forces on the relatively slender pushrod cause radial reaction forces and consequent friction at the interface between the pushrod and the outer tube. This can result in the applicator mechanism sticking in the closed position thus causing problems for the operating surgeon in disengaging the applicator from the closed clip.
Another problem with known applicators is the need to adjust the travel of the mechanism in order to achieve correct closure of the clip to an accurate position; such adjustment can be costly to achieve. It is important that the surgical clip is closed to an accurate position. If the clip is closed too tightly, the tubular anatomy may be severed, requiring the surgeon to apply further clips to severed ends of the tubular anatomy. Conversely, if applied clips are not closed sufficiently tightly, the tubular anatomy may not be properly occluded.
A further problem with known applicators is the requirement that the applicator must be made from expensive components in order to ensure that the surgical clips can be closed accurately, and to be able to perform many clip closure operations. In particular, in such an important piece of medical equipment, and especially one in which mechanical forces are transmitted (e.g. the force of the surgeon pulling the trigger, which is converted to a closing force on the clip), it is important that tolerances are carefully monitored and, if need be, adjusted in the manufacturing environment. This can be expensive, and increases the manufacturing cost of the applicator.
Appropriate design of applicator and its constituent components can mitigate some of the issues associated with this.
Other designs of applicators can require the surgeon to apply significant force to the trigger mechanism of the applicator in order to correctly close and latch the surgical clip, which can make the applicator difficult to manipulate and operate.
It is often necessary for the applicator to be inserted into a cannula during “keyhole” surgery. Existing clip applicators have a “pistol” handgrip which can make them difficult to manipulate into the correct position whilst at the same time operating the applicator (in particular providing adequate manual closure force) to close the clip.
It is an object of the invention to provide an applicator for surgical clips which requires less force to operate and to correctly close and secure a surgical clip than known applicators.
Another object of the invention is to provide an applicator which can precisely close and secure surgical clips to an accurate position.
A further object of the invention is to provide an applicator which may be more precisely manipulated than known applicators, whilst also being operable to close and secure accurately a surgical clip.
A still further object of the invention is to provide an applicator for surgical clips which is of a simpler and more robust design to such known applicators.
Yet another object of the invention is to provide an applicator for surgical clips which is easier and cheaper to manufacture than existing applicators
Such an applicator may be partially or completely disposable.